Novel greases



Patented Sept. 7, 1948 UNITED STATE Francis JQLicata, West Caldwell, Jass ignor to Nopco Chemical Company, Harrison, corporation of New J NoDrawing. 7 Original application August 14 1942, Serial No. 454,825, nowPatent No.

, 2,431,760, dated Decem this application Marc This invention relates toimproved aluminum base greases. I

Aluminum base greases are widely used for lubrication purposes onaccount of their waterproof characteristics, their heat resistancewithin certain limitations and their attractive appearance. However,thesegreases have certain disadvantages, notably their tendency toassume a jelly-like, rubbery texture upon heating above a certaincritical temperature; their tendency towards syneresis, or bleeding outof oil in storage and use; and their somewhat granular and crumblingstructure. Further, the oils contained in aluminum base greases must beof relatively high viscosity in order to form a stable grease.

Accordingly, it is an object of this invention to provide aluminum basegreases which will have a smooth, unctuous and greasy texture, and whichwill retain this texture when heated to elevated temperatures.

Another object is to provide an aluminum base grease which will notseparate oil upon standing.

Still another object is to provide an aluminum base grease in which alarger proportion of soap base may be incorporated than has hithertobeen possible.

The above and other objects are attained by this invention in aluminumbase greases which contain, in addition to aluminum soaps of saturatedhigher fatty acids, a small proportion of a barium soap of a higherfatty acid. The added barium soap serves to stabilize the colloidalstructure of the grease, preventing syneresis thereof during storage anduse, and restraining the tendency of the grease to assume a rubberytexture at high temperatures. Further, greases prepared according tothis invention are characterized by having a smoother and more unctuoustexture in comparison to aluminum base greases heretofore prepared andlikewise are capable of holding a substantially greater amount of soapfor a given consistency than is possible with aluminum base greasesheretofore prepared. The expressions aluminum base greases and aluminumsoaps as used herein are qualified in that, in each instance, thealuminum base or soap is that of an aluminum soap of a saturated higherfatty acid.

Except for the nonaluminum soap additive just mentioned, the greases ofthis invention will be constituted substantially the same as thealuminum base greases hitherto manufactured, containing in generalbetween about 2% and about 15% to 20% of aluminum soaps of saturatedClaims. (01. 252--36) j her 2, 1947. Divided and h 14,,1346, Serial No.

higher fatty acids, comprising essentially lubri v cating oils. Thepercentage of aluminum soap incorporated into the greases of thisinvention maybe slightly higher than in the usual aluminum base greasesin view of the softening tendency of the nonaluminum soap additive. Thealuminum content of the aluminum-soap may be varied between the usuallimits and will generally be such that the washed ash determined uponthe soapwill lie between about 4% and about 12%. Thefatty residues inthe aluminum soap may be of the types customarily used in aluminum basegreases, i. e., higher saturated fatty radicals on the order ofpalmitic, stearic, margaric, etc., radicals.

The fatty radicals in the barium soap may be any of the higher fattyacids having molecules containing upwards of 8 carbon atoms, and preferably upwardsof 16 carbon atoms. Preferably, butnot necessarily, thefatty acids should be saturated. A list of suitable fatty acids, thebarium soaps of-Which may suitably be employed in the greases-oi thisinvention, includes palmitic, stearic, arachidic, lauric, margaric,oleic, elaidic, erucic, and the like, fatty acids. Instead of thesoapsof purefatty acids, there may be employed soaps of suitable mixedfatty radicals coming within the requirements above set forth, such asthe mixed fatty radicals derivable from the animal and vegetable oils,fats and waxes such as tallow, corn oil, cottonseed oil, hydro genatedfish oils, and the like. Likewise, the naphthenic acids are suitablecomponents of the nonaluminum soaps incorporated into greases accordingto this invention. The mol ratio of metallic and of fatty radicalspresent in the said soaps may vary; in general, at least one of thevalencies of the metal should be combined with fatty radicals, but ahigher ratio may desirably be employed. Usually, the neutral soap willbe employed.

The amount of barium soap incorporated into the grease of this inventionmay vary, depending on the properties desired in the final product, butin general this amount will be only a small fraction of the amount ofthe aluminum soap present. Roughly, the objects of this invention can beattained by the addition of from about 0.1% to about 5% of the bariumsoap, based upon the total weight of grease. In general, the higher thepercentage of barium soap, the softer the resulting grease will be forany given percentage of aluminum soap, and advantage can be taken ofthis fact to add a considerably greater total amount of soaps to thegrease than has heretofore been possible with aluminum base soaps.

The manner of preparing greases of this invention can. follow anyconventionalv practice, this not being critical to the invention.Conveniently, the aluminum soap, barium soap,

lubricating oil and any other desired ingredients.

With the above discussion in mind, there is.

given herewith an example of a grease prepared in accordance with thisinvention. All parts.

given are by weight:

Example Parts Aluminum stearate (8% Washed ash) 11 Barium soap (neutralstearate) 1 Paraflin oil (100 sec. viscosity 100 F.) 88

The above ingredients were heated to 150 C. with stirring, and slowlycooled to room temperature; The resultinggrease-was soft with'a smoothtexture and free from bleeding. On reheating, it melted withoutpassingthrough the rubbery stage.

From the above, it will be seen that the greases provided by'thisinvention aredistinguished from similar greases heretofore prepared inthat they do not become rubbery upon heating. This is highlyadvantageous since the greases do not-lose their lubricating propertiesupon overheating of the surfaces to which they are applied. Further,greases according to this invention possess a smoother and more unctuoustexture than aluminum base greases heretofore prepared. Still further,the greases of this invention may have a higher net soap content, can bemade from less viscous oils without danger of bleeding out of the oil,and'exh'ibit a higher degree of water-resist- 4 ance than aluminum basegreases of the prior art. Finally, greases according to this inventionare highly stable in storage and use against any separation or syneresisof the oils contained therein.

This application is a division of my application Serial No. 454,825filed on August 14, 1942, now Patent No. 2,431,760, dated December 2,1947.

I therefore claim:

1. Alubricating grease comprising mineral oil, 2%.to 20% of an aluminumsoap of a saturated higher-fatty acid and 0.1% to 5.0% of a barium soapof a higher fatty acid, the quantity of the barium soap being only afraction of that of the aluminum soap.

2'. A lubricating grease comprising mineral oil, 2% to 20% of analuminum soap of a saturated higher fatty acid and 0.1% to 5.0% of abarium soap of a saturated higher fatty acid, the quantity of the bariumsoap being only a fraction of that of the aluminum soap.

3. A lubricating grease comprising mineral oil, to 20% aluminum stearateand 0.1% to 5.0% of a barium soap of a higher fatty acid, the quantityof the barium soap being only a fraction of the aluminum soap.

4. A lubricating grease comprising mineral oil, 2% to 20% aluminumstearate and 0.1% to 5.0% of a barium soap of a saturated higher fattyacid, the quantity of the barium soap being only a fraction of that ofthe aluminum soap.

5. A lubricating grease comprising mineral oil, 2% to 20% aluminumstearate and 0.1% to 5.0% barium stearate, the quantity of the bariumsoap being only a fraction of that of the aluminum soap.

FRANCIS J. LICATA.

REFERENCES CITED i The'following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,625,969 Willock et al Apr. 26,1927 2,266,544 Freuler- Dec. 16, 1941 2,332,247 Morway et a1 Oct. 19,1943 2,379,245 Morway et a1 June 26, 1945 2,397,956 Fraser Apr. 9, 1946

